With the wide coverage of the WAMS in power system, it is possible to detect the static parameters of power grid branch with PMU measurement. The paper presents a method, that is, by the reformation of state space and linear static state estimation. To improve branch parameter computation redundancy, KCL equations are added to the measurement equation which is presented in parameter space. Through a combination of global detection and local identification, combined with much statistical analysis of measurement profiles, the adverse effects brought by the lack of precision of PMU measurement can be minimized. Finally, a New England 39 buses test system and a practical example are presented to verify the effectiveness of the proposed algorithm.